Wednesday, January 12, 2011
Know Your 800 Pound Gorilla, Part Two: Determining Tree Height
A quick and fairly accurate method for height measurement is nothing more complicated than a stick in your hand for creating similar triangles. Look at the diagram above, (Click on photo to enlarge.) and note that segment ab is the same length as segment bc. Point a (A), is your eye, which must not move due to head bobbing during the measuring process. If you set up your stick properly, the distance AB will be equal to distance BC.
Back away from the tree you wish to measure, tip your head back so your eyes can easily roll to the top of the tree, extend the arm which holds your stick, and place the top of the stick at the corner of one eye.
Hardwood trees usually have broad crowns, so the top center of the tree is often hard to spot. You have to be careful not to measure to the edge of a broad crown, or the height will be exaggerated greatly. Practice this a bit while the leaves are down to get a feel for it.
Next time: Diameter measurement, and segments.
Link Back to Part 1